1. Field of the Invention
The present invention relates to a touch sensor chip, a touch sensing apparatus including the same, and a method of controlling noise of a touch panel, and more particularly, to a touch sensor chip which varies a driving frequency according to the occurrence of noise, a touch sensing apparatus including the touch sensor chip, and a method of controlling noise of a touch panel.
2. Description of the Related Art
A touch sensing apparatus includes a touch panel and recognizes a user's screen touch or gesture as input information. Touch panels of touch sensing apparatuses are classified into resistive, capacitive, ultrasonic, and infrared touch panels according to their driving method. Of these touch panels, capacitive touch panels are drawing much attention due to ease of multi-touch input.
A capacitive touch sensing apparatus suffers from various types of noise. One of the types of noise is environmental noise caused by the environment around the touch sensing apparatus. The environmental noise denotes noise generated by electromagnetic interference (EMI) or ground (GND) fluctuation that occurs in electronic devices other than the touch sensing apparatus. Generally, a touch panel of a touch sensing apparatus is placed on a display panel which displays images. Therefore, the touch panel may be interfered by a driving signal that drives the display panel as well as by other electronic devices around the touch panel.
If a noise occurs in the touch panel due to the environmental noise, the touch accuracy of the touch panel can be reduced. For this reason, a touch sensing apparatus that can flexibly deal with the environmental noise is required.